by EBSCO Medical Review Board

Here are the basics about each of the medicines below. Only common problems with them are listed.

Prescription Medicines

Levothyroxine (LT4)

  • Levothyroxine (T4)

Triiodothyronine (T3)

  • Liothyronine

Levothyroxine (T4)

Levothyroxine is a medicine that replaces the missing thyroid hormone thyroxine. It is taken as a pill or liquid. The dose a person is given will depend on how much of the missing hormone needs to be replaced. It make take several weeks for it to ease symptoms. A blood test will need to be done to recheck hormone levels to make sure a person is getting the right dose.

Problems may be:

  • Appetite changes or weight loss
  • Headache
  • Allergic reaction
  • Nausea and vomiting
  • Nervousness or irritability
  • Shaking
  • Menstrual changes
  • Diarrhea
  • Sweating
  • Leg cramps and swelling
  • Problems sleeping
  • Breathing problems
  • Fast or irregular heartbeat or chest pain

Liothyronine (T3)

Liothyronine (T3) is a short-acting thyroid hormone. It is not used as often as levothyroxine (T4). It is taken as a pill. It is often given to people whose thyroid has been removed to treat thyroid cancer. It is sometimes used with levothyroxine. The dose a person is given will depend on how much of the missing hormone needs to be replaced. It make take several weeks for it to ease symptoms. A blood test will need to be done to recheck hormone levels to make sure a person is getting the right dose.

Problems may be:

  • Appetite changes or weight loss
  • Headache
  • Allergic reaction
  • Nausea and vomiting
  • Nervousness or irritability
  • Shaking
  • Menstrual changes
  • Diarrhea
  • Sweating
  • Leg cramps and swelling
  • Problems sleeping
  • Breathing problems
  • Fast or irregular heartbeat or chest pain

References

Hypothyroidism (underactive thyroid). National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/endocrine-diseases/hypothyroidism. Accessed May 4, 2022.

Hypothyroidism in adults. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/hypothyroidism-in-adults. Accessed May 4, 2022.

Revision Information